Can one evidence set satisfy SOC 2, ISO 27001 and CMMC at once?

Practitioners should leverage a unified control framework or mapping exercise to identify common controls and practices across SOC 2, ISO 27001, and CMMC. This approach facilitates the collection of 'common denominator' evidence, such as access control logs, incident response plans, and risk assessments, which can support multiple compliance efforts. For instance, evidence demonstrating robust logical access controls is relevant to SOC 2's Security criteria, ISO 27001's A.9 (Access Control), and CMMC's AC (Access Control) domain. This strategic alignment reduces redundant effort and streamlines audit preparation, optimising resource allocation.

However, organisations frequently err by assuming generic evidence suffices for all frameworks. SOC 2 requires an auditor's opinion on the operating effectiveness of controls against Trust Services Criteria, often necessitating specific testing evidence. ISO 27001 demands a certified Information Security Management System (ISMS), requiring evidence of management review, internal audits, and continual improvement processes. CMMC, particularly at higher levels, mandates specific documentation of processes, policies, and plans directly linked to NIST SP 800-171 practices, alongside evidence of their implementation and institutionalisation. Each framework's unique reporting format and assurance requirements necessitate tailored evidence and distinct assessment processes.